1. Field of the Invention
The invention relates to the catalytic oxidation of dilute aqueous organic compounds, and particularly, to the catalytic oxidation of dilute aqueous compounds with hypochlorous acid. More particularly, the invention relates to the catalytic oxidation of dilute aqueous formaldehyde with hypochlorous acid.
2. Prior Art of Interest
Past practices relating to water treatment for the purpose of rendering innocuous formaldehyde and other organic compounds by oxidation or otherwise have been accompanied by a number of disadvantages.
Moses et al, Canadian Patent No. 539,300 (1957), discloses a water treatment process which achieves oxidation of organic compounds by introducing oxygen to a waste stream in the presence of a platinum catalyst, the waste stream being heated to a temperature in the range of 100 to 350 degrees Centigrade at a pressure of 200 to 2500 psi. The primary disadvantage of this process is the high cost of heating and pressurizing the waste stream. The use of a platinum catalyst is an additional factor.
Various biological processes are available which utilize formaldehyde and other organic compounds as nutrients. Such processes require long reaction times and therefore large holding tanks, a significant cost factor.
Junkermann et al, U.S. Pat. No.4,104,162, discloses a method for oxidizing formaldehyde in aqueous streams by the addition of hydrogen peroxide and sodium hydroxide. This method is attended by multiple disadvantages including the high cost of hydrogen peroxide and photodegradation upon exposure to light, incompleteness of formaldehyde oxidation after considerable reaction time, and the presence of a potential disposal problem in light of such reaction products as formate and hydrogen gas.
Murphy et al, Environmental Science Technology, Vol. 23, pp. 166-169 (1989), disclose a water treatment process wherein formaldehyde is oxidized by hydrogen peroxide in the presence of ferric chloride as a catalyst. Disadvantages of this process, common to the Junkermann et al process, are the high cost of hydrogen peroxide relative to chlorine, sodium hypochlorite or calcium hypochlorite, and the requirement of greater than stoichiometric amounts of hydrogen peroxide to compensate for autodecomposition of the oxidant. Actual requirements for hydrogen peroxide may be 3 to 5 times the quantity based on reaction stoichiometry. Associated costs would be significant.